package com.xiao.tripmateai.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.xiao.tripmateai.constant.UserConstant;
import com.xiao.tripmateai.exception.BusinessException;
import com.xiao.tripmateai.exception.ErrorCode;
import com.xiao.tripmateai.model.domain.User;
import com.xiao.tripmateai.model.dto.user.UserEditRequest;
import com.xiao.tripmateai.model.vo.LoginUserVO;
import com.xiao.tripmateai.model.vo.UserVO;
import com.xiao.tripmateai.service.UserService;
import com.xiao.tripmateai.mapper.UserMapper;
import jakarta.servlet.http.HttpServletRequest;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.util.DigestUtils;

import java.util.List;

/**
* @author xiao
* @description 针对表【user(用户表)】的数据库操作Service实现
* @createDate 2025-07-27 11:25:42
*/
@Service
@Slf4j
public class UserServiceImpl extends ServiceImpl<UserMapper, User>
    implements UserService{

    /**
     * 用户注册
     * @param userName 用户账户
     * @param userPassword 用户密码
     * @param checkPassword 确认密码
     * @return
     */
    @Override
    public long userRegister(String userName, String userPassword, String checkPassword) {
        //1.校验参数
        if(StrUtil.hasBlank(userName,userPassword,checkPassword)){
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "参数为空");
        }
        if(userName.length() < 4){
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "用户账号长度不能小于4");
        }
        if (userPassword.length() < 8 || checkPassword.length() < 8) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "用户密码过短");
        }
        if (!userPassword.equals(checkPassword)) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "两次输入的密码不一致");
        }
        // 2. 检查用户账号是否和数据库中已有的重复
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("userName", userName);
        long count = this.baseMapper.selectCount(queryWrapper);
        if (count > 0) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "账号重复");
        }
        // 3. 密码一定要加密
        String encryptPassword = getEncryptPassword(userPassword);
        // 4. 插入数据到数据库中
        User user = new User();
        user.setUserName(userName);
        user.setUserPassword(encryptPassword);
        user.setNickName("无名");
        boolean saveResult = this.save(user);
        if (!saveResult) {
            throw new BusinessException(ErrorCode.SYSTEM_ERROR, "注册失败，数据库错误");
        }
        return user.getId();
    }

    @Override
    public String getEncryptPassword(String userPassword) {
        // 加盐，混淆密码
        final String SALT = "xiao";
        return DigestUtils.md5DigestAsHex((SALT + userPassword).getBytes());
    }

    @Override
    public LoginUserVO userLogin(String userName, String userPassword, HttpServletRequest request) {
        // 1. 校验
        if (StrUtil.hasBlank(userName, userPassword)) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "参数为空");
        }
        if (userName.length() < 4) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "用户账号错误");
        }
        if (userPassword.length() < 8) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "用户密码错误");
        }
        // 2. 对用户传递的密码进行加密
        String encryptPassword = getEncryptPassword(userPassword);
        // 3. 查询数据库中的用户是否存在
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("userName", userName);
        queryWrapper.eq("userPassword", encryptPassword);
        User user = this.baseMapper.selectOne(queryWrapper);
        // 不存在，抛异常
        if (user == null) {
            log.info("user login failed, userName cannot match userPassword");
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "用户不存在或者密码错误");
        }
        // 4. 保存用户的登录态
        request.getSession().setAttribute(UserConstant.USER_LOGIN_STATE, user);

        return this.getLoginUserVO(user);
    }

    /**
     * 获取脱敏类的用户信息
     *
     * @param user 用户
     * @return 脱敏后的用户信息
     */
    @Override
    public LoginUserVO getLoginUserVO(User user) {
        if (user == null) {
            return null;
        }
        LoginUserVO loginUserVO = new LoginUserVO();
        BeanUtil.copyProperties(user, loginUserVO);
        return loginUserVO;
    }

    @Override
    public User getLoginUser(HttpServletRequest request) {
        // 判断是否已经登录
        Object userObj = request.getSession().getAttribute(UserConstant.USER_LOGIN_STATE);
        User currentUser = (User) userObj;
        if (currentUser == null || currentUser.getId() == null) {
            throw new BusinessException(ErrorCode.NOT_LOGIN_ERROR);
        }
        // 从数据库中查询（追求性能的话可以注释，直接返回上述结果）
        Long userId = currentUser.getId();
        currentUser = this.getById(userId);
        if (currentUser == null) {
            throw new BusinessException(ErrorCode.NOT_LOGIN_ERROR);
        }
        return currentUser;
    }

    @Override
    public boolean userLogout(HttpServletRequest request) {
        // 判断是否已经登录
        Object userObj = request.getSession().getAttribute(UserConstant.USER_LOGIN_STATE);
        if (userObj == null) {
            throw new BusinessException(ErrorCode.OPERATION_ERROR, "未登录");
        }
        // 移除登录态
        request.getSession().removeAttribute(UserConstant.USER_LOGIN_STATE);
        return true;
    }

    /**
     * 获得脱敏后的用户信息
     *
     * @param user
     * @return
     */
    @Override
    public UserVO getUserVO(User user) {
        if (user == null) {
            return null;
        }
        UserVO userVO = new UserVO();
        BeanUtil.copyProperties(user, userVO);
        return userVO;
    }

    @Override
    public List<UserVO> getUserVOList(List<User> userList) {
        return List.of();
    }

    @Override
    public void editUser(UserEditRequest userEditRequest, User loginUser) {

    }

    @Override
    public boolean isAdmin(User user) {
        return false;
    }
}




